Seal for earcup or the like



J. AILEO SEAL FOR EARCUP OR THE LIKE vApril 21, 1970 5 Sheds-Sheet 1Filed Dec. 26, 1968 INVENTOR. J c/fsa/u %/4 0 5% c QLM 'yr ram/fy April21, 1970 J. AILEO SEAL FOR EARCUP on THEYLIKE Filed Dec. 26, 1968 3Sheets-Sheet 2 ici. E

INVENTOR. J4c/(50/u" 4. fi/zfo J. AILEO SEAL FOR EARCUP OR THE LIKEApril 21, 1970 3 Sheets-Sheet 5 Filed Dec. 26, 1968 United States PatentInt. Cl. A42b 1/06 U.S. Cl. 2209 16 Claims ABSTRACT OF THE DISCLOSURE Aresilient annular head-engaging seal for attachment to the rim of anearcup or like cup-shaped structure adapted to be pressed against aportion of the human head to enclose such head portion, the seal havingat least one annular flange projecting toward and engageable with thehead surface upon pressure of the cup against the head, and at least onethin flexible annular fin disposed inwardly of but extending generallyparallel to the flange and projecting toward the head surface forengagement therewith. The seal may have inner and outer head-engagingannular flanges defining an annular channel between them, and aplurality of thin flexible annular fins disposed in this channel andprojecting therefrom toward the head, the height of the fins beingsufficient so that their edges engage and fold against the head surfacewhen the cup is pressed against the head.

CROSS-REFERENCE TO RELATED APPLICATION This application is acontinuation-in-part of the copending application of applicant herein,Ser. No. 730,- 264, filed May 20; 1968, for Sound Attenuating Earcups.

BACKGROUND OF THE INVENTION This invention relates to seals forprotective or like structures adapted to enclose a limited portion ofthe human face or head, and more particularly to seals adapted to becarried on the rim of a head portion enclosing structure for engagementwith the wearers head surface to provide sealing contact between theenclosing structure and the head. In an important specific aspect,

. the invention is directed to a sound-attenuating seal for an earcup orlike structure for shielding a head or face portion, such as the ear,from ambient noise.

. Sound attenuating earcup devices are commonly worn by personnelworking in environments where protection of the ears from ambient noiseis necessary. In many such environments a protective helmet is alsohighly desirable. Consequently, it is desirable for the earcups to beadaptable for wear either with a safety helmet or with some othersuitable supporting structure. Whether the supporting structure is ahelmet or not, it is usually provided with some means for pressing theearcup against the wearers head. A resilient sealing pad is mounted onthe rim of the earcup, so as to engage firmly and resiliently the humanhead in the area about the ear. The pressing means and the resilient padare intended to cooperate in closing all leakage paths by which externalsound waves might reach the wearers ear.

Certain persons have duties to perform in environments subject to highintensity sounds, e.g., in the vicinity of jet engines. As the enginepower outputs become greater, the sound intensities encounteredincrease, creating a demand for more effective sound attenuatingdevices.

The attempts to meet this demand have in the past taken one or both oftwo directions. One direction has "ice been to increase the force of thepressing means to close more completely the sound leakage paths. Theother direction has been to increase the mass, volume, or flexibility ofthe resilient pad on the rim of the earcup. Increasing the force of thepressing means necessarily detracts from the comfort of the wearer, andthereby tempts him to remove the earcups under conditions which may bedangerous to his hearing. Increasing the mass or volume of the pad alsodetracts from the wearers comfort.

Resilient annular face or head-engaging seals may also be employed withother structures for enclosing a portion of the face or head. As oneexample, to enable clear voice communication under conditions of highambient noise, it is sometimes desirable to enclose a portablemicrophone in a sound-attenuating housing which is pressed against andsurrounds the mouth area of the user. A resilient face-engaging pad maybe mounted on the rim of such a housing to serve a purpose similar tothat of the above-mentioned earcup seal, namely to providesound-attenuating sealing contact between the housing and the usershead. In addition, resilient seals may be employed with masks or gogglesto seal the wearers eyes, nose and/or mouth from exposure to harmfulgases or vapors. As in the case of earcup seals, it is desirable in eachof the foregoing instances to achieve superior sealing eflicacy withminimum discomfort to the user 0 wearer.

In the above-identified copending application there is described asound-attenunating seal for an earcup, comprising a resilient padincluding an elliptically annular base having one side adapted forattachment to the rim of an earcup shell, and a flange on the baseadapted to engage the wearers head, the flange projecting from the basein a direction away from the aforementioned one side and radiallyoutward with respect to the axis of the shell, so that the flange isdeflected from its unstressed position when in engagement with thewearers head, this deflection being effective to stress a position ofthe pad in tension, the tension-stressed position being effective tohold the flange firmly but lightly against the wearers head. Preferably,the pad has a second flange spaced radially inwardly from thefirst-mentioned flange with respect to the axis of the shell; the secondflange projects from the base in a direction away from theaforementioned one side and radially inward with respect to the shellaxis, the flanges defining between them a channel which is the portionof the pad that is stressed in tension as mentioned above. It is alsopreferred that the channel and flanges have smooth, rounded contours andthat the first (outer) flange be shaped to conform to the head of awearer. The described structure is found to provide a comfortable yethighly effective sound-attenuating seal when mounted on an earcup thatis pressed relatively lightly against the wearers head.

SUMMARY OF THE INVENTION is to be understood that the geometric centerof the seal is a point located at the geometric center of the annulusdefined by the seal, such point lying approximately on the axis of theearcup shell in embodiments of the invention designed for use with anearcup. Also, it is to be understood that by the term thin flexible finas used herein is meant an upright bladelike member having an extent inthe direction toward the wearers head which is large in relation to thethickness of the fin, and resiliently bendable along its free edge inresponse to light pressure, but sufficiently stiff to substantiallyretain its upright position in the absence of such pressure.

In preferred embodiments, the seal of the invention includes a pluralityof such fins, disposed in more or less closely spaced relation to eachother between the outer and inner (i.e. first and second)flanges of theseal. When the seal is pressed against the head, the edges of the finsfold or crumple against the head surface, so as to provide a tortuous,sound-attenuating path for sound waves which may pass the flanges; eachfin constitutes a sound-attenuating barrier and, as thus folded orcrumpled, cooperates with the base and flanges of the seal, the headsurface, and other fins to define between the shell and head pluralsmall air spaces.

In this way, provision of thin fins in accordance with the presentinvention affords aspecially advantageous sealing action, as forattenuation of sound, yet with comfort to the wearer and without addingexcessive mass or volume to the seal.

The fins may be formed integrally with (or bonded to) the seal base andflanges, or may be formed integrally with (or bonded to) a separateflexible base plate of annular configuration conforming to the annularshape of the seal. If a base plate is used, its rear surface may bebonded to the channel portion of the seal throughout its extent, or thebase plate may be in effect suspended across the channel (to create anannular air gap between plate and channel that further aids in soundattenuation), being bonded along its edges to the first and secondflanges of the seal. For assured contact with the wearers head, the finsproject above the slope of a line drawn between the first and secondflanges; they may all project to the same height above such slope, orthe central ones of an array of parallel fins may project to a greaterheight than those fins of the array which are closest to the twoflanges! Also, the fins may be either parallel to each other or arrangedso as to have spaced lateral contact with each other to form a hexagonalor like pattern. In a further modification, thin fins may extend alongthe crests of one or both flanges to afford assured sealing at points atwhich the flanges may encounter localized depressions in the wearershead. a

While the invention has been described as embodied in structures adaptedfor use with an earcup, it may also be embodied in seals for use withother cup-shaped or like devices for surrounding and enclosing portionsof the human head, such as microphone housings, masks, and goggles, toseal the enclosed head or face portion against ambient sounds and/ornoxious fumes, gases or vapors. In this regard it may be explained thatthe term annular seal as herein employed refers to a closed-ring sealwhether of annular, elliptical, or other (e.g. irregular) shape. 4

In addition, the invention contemplates the provision of structures forenclosing a portion of a human head, including a rigid cup-shaped shellhaving an opening with an annular rim and a seal of the type describedabove mounted on the rim.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an elevational sectionalview of a soundattenuating earcup structure incorporating a sealembodying the present invention in a particular form;

FIG. 2 is a fragmentary elevational view of the seal of FIG. 1, lookingfrom the seal side of the earcup;

FIG. 3 is a fragmentary sectional elevational view taken on line 33 ofFIG. 2;

FIG. 4 is a view similar to FIG. 3, but showing the seal engaging thehead of a wearer;

FIG. 5 is a view taken on line 55 of FIG. 4;

FIG. 6 is a fragmentary sectional view of a modified form of sealembodying the invention, taken along the line 33 of FIG. 2;

FIG. 7 is a sectional view of another modified form of seal embodyingthe invention;

FIG. 8 is a sectional view of a further modified form of seal embodyingthe invention;

FIG. 9 is a fragmentary sectional view of yet another modified form ofseal embodying the invention;

FIG. 10 is a fragmentary elevational view of a still further modifiedform of seal embodying the invention;

FIG. 11 is a fragmentary elevational view of another modified form ofseal embodying the invention;

FIG. 12 is a perspective view of a sound-attenuating microphone housinghaving a seal embodying the invention; and

FIG. 13 is a fragmentary sectional view taken on line 13-13 of FIG. 12.

DETAILED DESCRIPTION Referring first to FIGS. 1 through 5, the inventionin the form there shown is illustrated as embodied in a seal 10 for asound-attenuating earcup. This earcup may be supported by meansdisclosed in my copending application, Ser. No. 686,500, filed Nov. 29,1967, and is intended to be biased lightly against the head of thewearer. For example, the biasing means may be that disclosed in saidcopending application. It will be understood, of course that this issimply one convenient way of biasing the earcup and is not to be takenas a limitation on the present invention.

The earcup comprises a rigid cup-shaped shell 12, constructed of plasticor other suitable material. The open end of the shell is provided withan inwardly extending flange 14, which may be either an integral part ofthe shell or a separate element suitably attached to the rim of theshell, as, for example, by bonding. This flange serves to provide abroader base than the rim of the shell for supporting the seal 10. Anoutwardly extending pair of spaced peripheral flanges 16 on the earcupshell 12 define a channel for receiving a shield 17 on which the shellis supported.

The seal 10 is a resilient pad, and is elliptically annular in shapelike the rim of the earcup shell 12, so as to encircle the ear of thewearer. It is fabricated of a softly resilient, preferably moldablematerial, such as a sponge plastic. While many of the sponge rubbers aresuitable for the present invention, it is presently preferred to use aresilient sponge silicone. The term sponge plastic as used in thisspecification is intended to be a generic term inclusive of spongerubbers and sponge silicones, as well as other sponge plastic materials.The seal may be molded in accordance with known procedures for moldingsuch materials.

As seen in cross-section, the seal 10 comprises a base 18 adapted forattachment, such as by bonding, to the flange 14 of the shell 12, anddivergent inner and outer head-engaging flanges 20 and 22. Each of theflanges 20 and 22 terminates in a smoothly curved surface forcomfortable engagement with the head of the wearer. The flanges 20 and22 define a broad, smoothly curved channel 24 between them, andrespectively extend beyond the inner and outer peripheral walls of thebase 18, so that when the flanges are pushed into engagement with thewearers head, as shown in FIG. 4, the material at the bottom of thechannel is stretched and thereby stressed in tension. This tension tendsto pull the flanges into a more firm engagement with the head and thusgreatly improves the effectiveness of the seal against external soundswithout increasing the wearers discomfort. A total biasing force actingagainst the earcup on the order of 6 to 8 ounces is sufficient toachieve this sealing effect, and as the force is spread around theentire periphery of both flanges 20 and 22, the pressure felt by thewearer is extremely light.

The seal is provided with a fiap 26 which overlies the outer edge of theflange 14 and the outer rim of the shell 12 so as to hold the seal inplace on the shell. Within the flap 26, preferably at its innermostcup-engaging surface, there is molded a coil spring 28, which has anunstressed length smaller than the periphery of the earcup and hence iseffective to hold the seal firmly in position on the shell. This spring28 may extend continuously around the periphery of the seal 10 or anembedded wire may be employed in place of one or more portions of thespring, with a spring connecting the ends of the wire.

In order to conform to the head of the wearer, the head-engaging surfaceof the seal may be contoured. This is accomplished by molding the outerflange 22 to follow the average surface of a human head along a pathencircling the ear. The inner flange 20 is preferably shorter than theouter flange 22 (i.e. in elevation above the flange 14) and its tip maylie in a single plane; the inner flange may even be omitted in someconstructions.

The features of the earcup seal thus far described are shown and claimedin applicants aforementioned copending application Ser. No. 730,264, andafford an earcup seal which is not only more comfortable to the wearerof the earcup than previous pad structures but is also more effective inattenuating external sounds.

In accordance with the present invention, the seal structure of FIGS.l-5 further includes a plurality of thin, resiliently flexible annularfiins 30 which project from the channel 24 between the inner and outerflanges 20 and 22, and extend generally perpendicular to the wearershead. These thin fins are higher than the flanges 20 and 22, i.e. inelevation above flange 14; hence they are first to engage the wearershead (before flanges 20 and 22 engage the head) when the device is used.As shown in FIGS. 4 and 5, the thin fins are easily bendable so thatthey fold and accommodate themselves to the head contours when theearcup is in place on the wearers head. Each thin fin acts as asound-attenuating barrier and in conjunction with the flanges 20 and 22serves to further reduce the transmission of external sound or vapor tothe vital openings in the head. While a single thin fin 30 presents someadvantages as a barrier, it is preferable to use a plurality of thinfins, as shown.

More particularly, in the embodiment of FIGS. l5, plurality ofelliptically annular fins 30 (e.g. six fins) are shown interposedbetween the inner and outer flanges 20 and 22 and extending in spacedsubstantially parallel (i.e. concentric) relation to each other and tothese flanges. The fins in the seal of FIGS. l-5 are fabricated of thesame material as the seal base and flanges (eg a silicone), for exampleby molding, and are, formed integrally with or bonded'directly to thebase 18, projecting upwardly from the surface of the channel 24. Whenthe earcup is in use, pressed against the wearers head with the sealengaging the head, the free edges of the fins 30 fold over against thesurface of the head in a more or less overlapping manner substantiallythroughout the annular extent of the seal so as to divide the air spacedefined between the head and the seal flanges and channel into pluralsmall irregular air spaces.

While the fins 30 are shown in FIGS. l-5 as projecting verysubstantially above the flanges 20 and 22 (i.e. in elevation above theearcup flange 14) in one specific example of an effective seal embodyingthe invention, the fins project for a distance of approximatelyone-eighth inch above a line 31 extending radially (with respect to theaxis of shell 12) from the crest of the inner flange 20 to the crest ofthe outer flange 22. Alternatively, as shown in FIG. 6, those fins 30awhich are centrally disposed with respect to the seal flanges 20 and 22may be higher than the fins 30b respectively adjacent to the two sealflanges, being arranged (for example) so that the free edges of thearray of fins, as seenin the cross-sectional view of FIG. 6, lie along acurve that is convex in the direction facing the wearer. In either case,the fins should project above the aforementioned line 31 defined by thecrests of the two seal flanges, for assured sealing contact with thewearers head (i.e. so that the free edge of each fin is in substantiallycontinuous contact with the head throughout the full annular extent ofthe seal when the seal is in place); and it is preferred that the finsrespectively closest to the inner and outer seal flanges 20 and 22 bespaced sufficiently from, and be sufficiently low in relation to, therespectively adjacent flanges so that they do not tend to fold over thecrests of the flanges when the cup is pressed against the wearers head,as such folding might create sound-transmission passages or spacesbetween the flanges and the wearers head.

FIGS. 7, 8 and 9 illustrate further modified embodiments of theinvention, again arranged for use with an earcup shell 12, wherein theplural parallel annular fins 30 are connected to a flexible andrelatively thin base sheet 32, which is somewhat thicker than the finsand may (like the fins themselves) be fabricated of the same material asthe seal base and flanges, eg a silicone. The base sheet 32 in theseembodiments is elliptically annular in shape, conforming generally tothe configuration of the seal base 18, and the fins 30 (formedintegrally with or. bonded to the base sheet) project toward the wearershead from the front major surface of the base sheet, in generallyperpendicular relation to that surface.

In the embodiment of FIG. 7, the entire back surface of the base sheet32 is continuously bonded to the surface of the channel 24 of the sealso that the fins 30, as before, in effect project from the seal base 18toward the wearers head. It may be noted that in FIG. 7 the fins areshown as progressively increasing in height in a direction outward fromthe axis of the shell 12. Also, in FIG. 7, the free edges 33 of the finsare shown as being uneven .rather than smooth. The uneven edges of thesefins tend to cause the fins to lie desirably flat against the wearershead rather than forming wrinkles.

In the embodiment of FIG. 8, the base sheet 32 is shown as bonded onlyalong its opposite side edges to the respective seal flanges 20 and 22,at localities partway up the side walls of these flanges within thechannel 24 but below the crests of the flanges, so that the crests ofthe flanges project above the base sheet. The central portion of thebase sheet is thus free, and cooperates with the channel 24 to define(i.e. between the channel and base sheet) a closed air pocket 34, whichaids in sound attenuation; one or more small openings (not shown in FIG.8) may be made in the base sheet to vent the pocket 34 for purposes ofpressure equalization, especially if the base sheet is relatively thickand/ or stiff. Preferably, the width of the base sheet between itsattached edges (i.e. the width of the free portion of the base sheet) issomewhat greater than the transverse distance across the channel 24between the localities of attachment of the channel surface to theseedges; and preferably, also, the width of this free portion of the basesheet is such that the sheet will be somewhat stressed in tension whenthe earcup is pressed against the wearers head as an aid in holding thefins firmly against the head.

In this or other embodiments of the invention, such as those alreadydescribed, a further elliptically annular thin flexible fin 36 may beformed on or bonded to the crest of the outer seal flange 22 (as shownin FIG. 8), extending entirely around the flange crest and projectingtherefrom toward the wearers head. This fin 36 aids in forming a secureseal between the flange and the head especially at regions of localizedbony depressions of the head to which the flange may not fully conformeven when pressed against the head. A similar thin flexible annular fin36a (also shown in FIG. 8) may be formed on or bonded to the crest ofthe inner seal flange 20, for the same purpose of aiding in providing acomplete seal between the inner flange and the head.

sheet and the channel 24. Pressure equalization apertures 40 for thisair pocket may be provided in the base sheet.

The fins of the invention may be locally bent, waved or partially foldedtransversely of their length and a plurality of fins so shaped may bedisposed to cooperate to define a honeycomb or grid pattern, withportions or fold edges of adjacent fins touching or bonded together. Twoexamples of such arrangement are shown in FIGS. and 11. FIG. 10illustrates a seal having a plurality of thin flexible annular fins 42generally similar to the fins 30 of the embodiments of the inventiondescribed above, and extending in generally parallel relation to theinner and outer seal flanges and 22, but regularly bent transversely oftheir length so as to cooperate to form a honeycomb pattern defininghexagonal air spaces 44 between the fins. In FIG. 11, the fins 46 are sobent as to cooperate to form a grid pattern defining diamond-shaped airspaces 48 between them.

Although the seal of the invention has been described as arranged foruse with an earcup, it may also be employed with other types ofstructures adapted to enclose a portion of the head or face, for soundattenuation or other sealing purposes. For example, in FIG. 12 there isshown a microphone housing 50 comprising a cupshaped rigidsound-attenuating shell 52 having straps 54 adapted for connection to asupporting structure (e.g. a helmet) on a wearers head to position thehousing in front of the wearers mouth. The shell 52 contains amicrophone 56, and has an opening 58 defined by an annular rirn shapedto surround the wearers mouth, the shell serving to enclose the moutharea and thus to shield the microphone against ambient noise. Secured tothe rim of opening 58 is a resilient annular seal 60 embodying thepresent invention and corresponding generally to the seal 10 of FIGS.1-5 but shaped to conform to the microphone housing rim rather than toan earcup rim, as shown in FIG. 13. Like the seal 10, the seal 60includes a plurality of thin flexible annular fins extending between andgenerally parallel to inner and outer seal flanges 20 and -22 forengagement with the wearers face, to provide a sound-attenuating seal,when the housing 50 is pressed lightly against the face as by means ofthe straps 54.

I claim:

1. A softly resilient seal adapted for attachment to the rim of astructure for enclosing a portion of the human head, and for engagementwith the head of a wearer along an area surrounding the head portion tobe enclosed, comprising:

(a) a resilient annular base having one side adapted for attachment tosaid structure rim; and

(b) a first resilient annular flange projecting from said base in adirection away from said one side and radially outward with respect tothe geometric center of the seal, so that the flange is deflected fromits unstressed position when in engagement with the wearers head thusstressing a portion of the seal so that said portion is effective tohold the flange firmly but lightly against the wearers head;

wherein the improvement comprises:

(c) and a second resilient annular flange spaced radially inwardly fromthe first flange with respect to the geometric center of the seal,saidsecond flange projecting from the base in a direction away from saidone side of said base and radially inward with respect to the geometriccenter of the seal, said flanges defining between them a channel whichis the (d) at least one thin flexible annular fin projecting from saidseal away from said one side of said base and disposed between saidflanges in substantially parallel relation to said flanges.

2. A seal as defined in claim 1, in which said fin projects beyond saidone flange.

3. A seal as defined in claim 1, including a plurality of .parallelspaced thin fins.

4. A seal as defined in claim 1, including at least one thin flexibleannular fin projecting from the crest of said annular flange in adirection away from said one side of said base.

5. A seal as defined in claim 1, including a plurality of spaced thinflexible annular fins projecting from said base away from said one side,disposed between said flanges and in substantially parallel relationthereto.

6. A seal as defined in claim 5, wherein the outer edges of said finsproject above a line extending radially with respect to the geometriccenter of the seal across the crests of said flanges.

7. A seal as defined in claim 6, wherein at least a central one of saidplurality of fins projects above the fins which are respectivelyadjacent to said flanges.

8. A seal as defined in claim 5, including a flexible annular baseplate, and wherein said plurality of fins are secured to the projectfrom one surface of said base plate, said base plate being secured atleast along its outer edges to said seal base.

9. A seal as defined in claim 8, wherein the surface of the base plateopposite to said one base plate surface is secured throughout its extentto the surface of said channel.

10. A seal as defined in claim 8, wherein said base plate is securedalong its opposite side edges to said first-mentioned and second flangesrespectively, the central portion of said base plate being spaced fromsaid channel so as to define an enclosed air space between said baseplate and said channel.

11. A seal as defined in claim 5, wherein said fins are secured to andproject from the surface of said channel.

12. A seal as defined in claim 5, wherein said fins have free edges ofirregular profile.

13. A seal as defined in claim 5, wherein each of said fins isrepeatedly bent transversely of its long dimension, the bent finscooperating to form a grid pattern.

14. Structure for enclosing a portion of the human head, comprising:

(a) a rigid cup-shaped shell dimensioned to enclose a portion of thehuman head and having an opening with an annular rim dimensioned tosurround the enclosed head portion; and

(b) a softly resilient seal adapted for attachment to said shell rim andfor engagement with the head of a wearer along an area surrounding thehead portion to be enclosed, said seal comprising:

(i) an annular base having one side adapted for attachment to said shellrim; and

(ii) a pair of annular flanges on said base adapted to engage thewearers head, said flanges projecting from the base in divergingdirections away from said one side, so as to define an annular channelbetween them, and so that said flanges are deflected from theirrespective unstressed positions when in engagement with the wearershead, such deflection being effective to stress the channel of the sealin tension, said tension-stressed channel being effective to hold theflanges firmly but lightly against the wearers head;

wherein the improvement comprises:

(iii) a plurality of thin flexible annular fins projecting from saidbase in a direction away from said one side and disposed between saidflanges 9 in spaced relation substantially parallel to said flanges,said fins having free edges projecting beyond said flanges for engagingthe wearers head.

15. Structure as defined in claim 14, wherein said shell 5 is an earcupadapted to enclose the wearers ear and wherein said rim-is ofelliptically annular configuration.

16. Structure as defined in claim 14, wherein said shell is a microphonehousing adapted to enclose the mouth area of the wearer and to contain amicrophone.

References Cited UNITED STATES PATENTS 1,527,802 2/1925 Huggins 179l822,990,553 7/1961 Ulrich et al 2209 FOREIGN PATENTS 796,004 1/ 1936France.

MERVIN STEIN, Primary Examiner 10 G. H. KRIZMANICH, Assistant Examiner

